Mail-In database reply address

I’ve created a Mail-In database with the email address : certificates.nl@weirminerals.com

So far so good,

but when I send emails from this mailbox to hotmail and gmail, I see different reply addresses…

Hotmail:

ENVNL:_Certificate_NL.WINET@weir.nl

Gmail:

ENVNL:_Certificate_NL.WINET"@weirservices.com

in both cases I cant reply to the email address.

How can I fix this issue?

Subject: anyone using Mail In databases?

Is there any body who works with “Mail-In” databases?